Off to ask for orlistat tomorrow.....any words of advice?

I don't know what my BMI is but I'm a size 20 and weigh over 17st. Been overweight my whole life (was a size 16 until DC1) and have never managed to lose a significant amount by myself. I've decided I don't want to go throguh my 30s like this but that I need some help to change it.......I've tried and failed so many times (probably literally hundreds).

Is it something GPs are generally reluctant to prescribe (i.e am I wasting my time?) or do you think it's worth a go? Feeling nervous about it for some reason. I've been fed the "eat less and exercise more" line so often that I'm worried they'll just completely dismiss me. Any words of wisdom gratefully received. Before 9am tomorrow to hop to it! TIA.

GP said no. Apparently they (the practice presumably) haven't found it to be particularly effective so don't generally prescribe it anymore. Basically sounds like they have given it to a lot of people who haven't bothered to adopt a healthy eating regime with it, and therefore haven't lost any weight.